I don't think it is brown, the cladding has a high reflection rate that has a jagged pattern, it is merely reflecting the construction materials and the ground. The cladding is silver as newer renders and test cladding have shown.

Made a collage of shenzhen construction projects over 200m that are being built RIGHT now, or are in prep/ ground work phase. These are not all of them, as some don't have any renders yet. On top of this, there are about a dozen construction projects with high-rise towers in the city, below 200m, which I have plotted on my google earth. Skyscraperpage.com is a bit outdated with shenzhen

OK, so obviously the 'brown' cladding was just shiny silver cladding reflecting the brown ground.
I have a feeling that the black 'cladding' may be covered with more silver eventually, I see silver in the render (previous post ) where the black currently is.

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